title: A systematic review of thyroid dysfunction in preterm neonates exposed to topical iodine.
abstract: OBJECTIVE
  To determine whether maternal exposure to iodine or neonatal exposure to topical iodine-containing solutions increases the risk of transient thyroid dysfunction in neonates born <32 weeks' gestation or <1.5 kg.
  
  
  METHODS
  Systematic review.
  
  
  METHODS
  Electronic searches were conducted using Medline and the Cochrane Library.
  
  
  METHODS
  A study was eligible for review if it reported neonatal exposure to topical iodine or maternal iodine exposure. The key outcome measure was neonatal thyroid function. The search had no restrictions on date of publication, type of study or language.
  
  
  RESULTS
  794 papers were identified during the initial search; 15 studies were fully reviewed. The incidence of (transient) hypothyroidism/hyperthyrotropinaemia following exposure to topical iodine ranged from 12 to 33 per 100 infants; the incidence in non-exposed infants was 0.
  
  
  CONCLUSIONS
  There is evidence that neonatal exposure to iodine-containing disinfectants causes thyroid dysfunction in infants born <32 weeks. None of the studies evaluated neurodevelopment. Larger scale studies are needed to determine definitively the nature of the relationship and the impact of exposure on neurodevelopment. In the meantime, it would seem prudent to restrict exposure of iodine-containing skin disinfectants in preterm infants; chlorhexidine might be a credible alternative.
authors.affiliation: Population Health Sciences, Medical Research Institute, Mackenzie Building, University of Dundee, , Dundee, Scotland.
authors.forename: Julie
authors.initials: J
authors.lastname: Aitken
authors.forename: Fiona L R
authors.initials: FL
authors.lastname: Williams
mesh_terms: D000287:Administration, Topical; D005260:Female; D006801:Humans; D006981:Hyperthyroxinemia / Q000139:chemically induced*; D007037:Hypothyroidism / Q000139:chemically induced*; D007231:Infant, Newborn; D007234:Infant, Premature; D017613:Iodine Compounds / Q000009:adverse effects* / Q000097:blood / Q000652:urine; D018811:Maternal Exposure; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D013961:Thyroid Gland / Q000187:drug effects*
chemical_list: D017613:Iodine Compounds
keywords: Neonatology; iodine; systematic review; thyroid hormones; toxicity